The present invention relates to a washing machine comprising a tub in which a drum is rotatably mounted, and a storage tank having a flow connection to the tub via a feeding line provided with a discharge pump and a three-port valve adapted to drive the flow to a drain line or to said storage tank. According to such features, a rinsing fluid can be stored in the storage tank and used in a subsequent washing cycle in order to reduce the overall amount of water used for washing laundry.